1. Field of the Technology
The present technology relates to a discharge tray apparatus that is provided in a copier or the like configured based on an image recording apparatus, the discharge tray apparatus housing recorded recording paper that has been recorded with the image recording apparatus.
2. Description of the Related Art
Presently, copiers, facsimile machines, printing apparatuses, and the like are absolutely necessary for paperwork in offices. These copiers, facsimile machines, printing apparatuses, and the like are configured based on an image recording apparatus, and recorded paper that has been recorded with this image recording apparatus is released, discharged, and placed on a discharge tray of a discharge tray apparatus provided in the image recording apparatus.
In this sort of copier or the like provided with an image recording apparatus or a discharge tray apparatus, ordinarily, recording paper is used that is paper finished in a rectangle of a fixed size, such as A-size or B-size paper. Also, one bundle of one or a plurality of pages of recording paper on which a series of content has been recorded is ordinarily referred to as one copy, and in a copier or the like, a plurality of individual copies, i.e. a plurality of copies, are often created in successive copy operations.
In such a case, it is necessary to divide the plurality of copies into copy units, and so there are demands to provide the discharge tray apparatus with a structure that performs this division. In order to realize this structure, in the conventional art there have been various proposals with respect to the discharge tray apparatus.
As a representative conventional example of a structure that performs this division, there is a structure that performs a so-called tray shift operation of the discharge tray, in which each time that each copy of one group of recording paper released to the discharge tray of the discharge tray apparatus changes, the discharge tray is moved in the horizontal direction approximately perpendicular to the discharge direction of the recorded recording paper (for example, see JP H11-130334A).
In the structure described in JP H11-130334A, a rack, in which a gearwheel is linearly configured approximately perpendicular to the discharge direction of recorded recording paper, is provided laid out on the back face of a bottom portion of the discharge tray of the discharge tray apparatus, and by rotating a pinion, which is a gearwheel that engages with this rack, forward or in reverse at a fixed speed with a motor or the like, this structure performs the above-described tray shift operation.
As a structure that performs this tray shift operation, other than the above structure described in JP H11-130334A, there is the following sort of structure. Specifically, a solenoid is provided on the back face of a bottom portion of the discharge tray of the discharge tray apparatus, the solenoid performing back and forth movement in the direction approximately perpendicular to the discharge direction of the recorded recording paper via attraction and release, and thus this structure performs the tray shift operation.
As described above, by using the tray shift operation of the discharge tray apparatus, recorded recording paper is placed at a different position on the discharge tray of the discharge tray apparatus for each copy unit, so it is possible to easily divide a plurality of copies into copy units.
Incidentally, in recent copiers and the like, increased processing speed is sought, and with this increased processing speed, the discharge speed of recording paper to the discharge tray in the discharge tray apparatus is increased, and the interval between sheets of discharged recording paper is shortened. Also, there is an increase in the number of sheets of recording paper in each copy made up of one recording paper group.
However, when performing the tray shift operation in the above sort of discharge tray apparatus, when dividing successively released and discharged recording paper according to the order in which the recording paper was released and discharged, among the successively released and discharged recording paper, after a preceding paper that is recording paper released and discharged earlier has been released and discharged, it is necessary to complete the above tray shift operation before a succeeding paper that is recording paper released and discharged next is released and discharged. If this is not done, the recorded recording paper will not be properly placed at a different position on the discharge tray of the discharge tray apparatus for each copy unit.
Therefore, due to increased processing speed as described above in copiers and the like, the tray shift operation time in which the above tray shift operation is performed becomes very short. For example, in recent ordinary copiers and the like, the recording paper transport interval (the interval distance in transport between the trailing edge of the above preceding paper and the leading edge of the succeeding paper) is about 50 to 100 mm, and under such a condition, in consideration of the ordinary stiffness and flexibility of the transported recording paper, it is necessary that the time necessary for the tray shift operation be not more than 1 second.
By adopting such a configuration, in the above discharge tray apparatus that performs the tray shift operation using a rack and pinion, or in the discharge tray apparatus that performs the tray shift operation using a solenoid, the tray shift operation is performed in a short time period, so at the point in time that the tray shift operation is completed, a shock is applied to the bundle of recording paper that has been placed on the discharge tray of the discharge tray apparatus, and for example, as shown in FIGS. 16 and 17, this recording paper bundle becomes disorganized.
FIG. 16 is a plan view of, in the case of the above conventional example, a discharge tray 41 at the point in time of, for example, finishing performance of three instances of the tray shift operation, and FIG. 17 is a front view thereof. As is understood from FIGS. 16 and 17, in the direction that the tray shift operation was performed, the top layer of recording paper bundles PS1 to PS3 that have been placed on the discharge tray 41 has moved further to the outside in the shift operation direction than the lower layer, and thus these recording paper bundles PS1 to PS3 have become disorganized.